Evaluating the use of marine subsidies by Arctic foxes without direct coastal access; insights from stable isotopes

The trophic structures of tundra ecosystems are often viewed as a result of local terrestrial primary productivity. However, other resources can be brought in through long-distant migrants or be directly accessible in coastal areas. Hence, trophic structures may deviate from predictions based on loc...

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Detalhes bibliográficos
Autores: Angerbjörn, Anders, Lidén, Kerstin, Roth, James D., Dalerum, Fredrik
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2024
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/376775
Acesso em linha:http://hdl.handle.net/10261/376775
https://api.elsevier.com/content/abstract/scopus_id/85193376352
Access Level:Acceso aberto
Palavra-chave:Delta 13C
Delta 15N
Allochthonous resources
Predator–prey relations
Fennoscandia
Ecological subsidies
Descrição
Resumo:The trophic structures of tundra ecosystems are often viewed as a result of local terrestrial primary productivity. However, other resources can be brought in through long-distant migrants or be directly accessible in coastal areas. Hence, trophic structures may deviate from predictions based on local terrestrial resources. The Arctic fox (Vulpes lagopus) is a small canid that may use marine resources when available. We used stable isotope values in Arctic fox fur and literature data on potential prey to evaluate Arctic fox summer resource use in a mountain tundra without coastal access. The dietary contribution of local prey, presumably mostly rodents, declined with declining rodent abundance, with a subsequent increased contribution of migratory prey relying on marine resources. Stable isotope values did not differ between this terrestrial area and an area with direct coastal access during years of high rodent abundance, but isotope values during low rodent abundances suggested less marine input than in a coastal population feeding primarily on marine prey. Our study shows that marine resources may be used by animals in areas without any coastal access, and we highlight that such partial coupling of ecosystems must be included in the modeling and assessments of tundra environments.